U.S. patent application number 13/515788 was filed with the patent office on 2012-12-20 for hand-power tool comprising an oscillation-damping device.
This patent application is currently assigned to Robert Bosch GmbH. Invention is credited to Juergen Bochert, Willy Braun, Carsten Diem, Roger Hahn, Patrick Heinen, Joerg Kaiser, Axel Kuhnle, Thomas Speda, Matthias Tauber, Christian Wiedemann.
Application Number | 20120318551 13/515788 |
Document ID | / |
Family ID | 43416962 |
Filed Date | 2012-12-20 |
United States Patent
Application |
20120318551 |
Kind Code |
A1 |
Kuhnle; Axel ; et
al. |
December 20, 2012 |
Hand-Power Tool Comprising an Oscillation-Damping Device
Abstract
A hand-power tool includes at least one oscillation-damping
device that has at least one damping spring and a damping mass. The
hand-power tool also includes a drive mechanism and a mechanism
housing. The mechanism housing has a housing cover which is
provided for closing a chamber in which the drive mechanism lies,
and the housing cover has at least one fixing mechanism that at
least partially fixes the oscillation-damping device in at least
one operating state.
Inventors: |
Kuhnle; Axel; (Freiberg
A.N., DE) ; Tauber; Matthias; (Bad Boll, DE) ;
Bochert; Juergen; (Stuttgart, DE) ; Diem;
Carsten; (Ludwigsburg, DE) ; Braun; Willy;
(Neustetten, DE) ; Wiedemann; Christian;
(Wiernsheim, DE) ; Kaiser; Joerg;
(Schwieberdingen, DE) ; Heinen; Patrick;
(Ludwigsburg, DE) ; Hahn; Roger; (Neuhausen,
DE) ; Speda; Thomas; (Holzgerlingen, DE) |
Assignee: |
Robert Bosch GmbH
Stuttgart
DE
|
Family ID: |
43416962 |
Appl. No.: |
13/515788 |
Filed: |
October 22, 2010 |
PCT Filed: |
October 22, 2010 |
PCT NO: |
PCT/EP2010/065979 |
371 Date: |
August 28, 2012 |
Current U.S.
Class: |
173/162.2 |
Current CPC
Class: |
B25D 2250/121 20130101;
B25D 17/24 20130101; B25F 5/006 20130101; B25D 2217/0092
20130101 |
Class at
Publication: |
173/162.2 |
International
Class: |
B25F 5/00 20060101
B25F005/00; B25D 17/24 20060101 B25D017/24 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2009 |
DE |
10 2009 054 723.1 |
Claims
1. A hand power tool comprising: at least one vibration absorber
device which has at least one absorber spring and an absorber mass,
and comprising a drive mechanism, and a mechanism housing having
(i) a housing cover that is provided configured to close a chamber
in which the drive mechanism is disposed, and (ii) at least one
fastening mechanism configured to, in at least one operating state,
at least partially fasten the at least one vibration absorber
device.
2. The hand power tool as claimed in claim 1, wherein the at least
one vibration absorber device and the drive mechanism are disposed
in the chamber closed by the housing cover.
3. The hand power tool as claimed in claim 1, wherein the housing
cover and the at least one vibration absorber device constitute a
structural unit configured to that can be preassembled.
4. The hand power tool as claimed in claim 1, wherein the at least
one absorber spring is configured to, in at least one operating
state, effect a fastening force upon the housing cover.
5. The hand power tool as claimed in claim 1, wherein: the at least
one absorber spring defines a spring direction, the drive mechanism
has a percussion mechanism, wherein and the percussion mechanism
and the at least one vibration absorber device are at least
partially disposed on at least one same plane that is aligned
perpendicularly in relation to a the spring direction.
6. The hand power tool as claimed in claim 1, wherein: the at least
one vibration absorber device has at least one first holding part
and one second holding part, wherein and the first holding part and
the second holding part are supported against each other through
the at least one absorber spring.
7. The hand power tool as claimed in claim 1, wherein the at least
one vibration absorber device has at least one holding part and has
at least one spring receiver that, in at least one operating state,
exerts an acceleration force upon the absorber mass and, in at
least one operating state, supports a counter force of the
acceleration force on the at least one holding part.
8. The hand power tool as claimed in claim 7, wherein the at least
one vibration absorber device has at least one support element that
is configured to, in at least one operating state, press the spring
receiver against the absorber spring.
9. The hand power tool as claimed in claim 1, wherein the at least
one absorber spring is disposed entirely in an axial region of the
absorber mass.
10. (canceled)
Description
PRIOR ART
[0001] The invention is based on a hand power tool as claimed in
the preamble of claim 1.
[0002] Already known from EP 1 736 283 A2 is a hand power tool
comprising at least one vibration absorber device, which has at
least one absorber spring and an absorber mass, and comprising a
drive mechanism and a mechanism housing.
DISCLOSURE OF THE INVENTION
[0003] The invention is based on a hand power tool comprising at
least one vibration absorber device, which has at least one
absorber spring and an absorber mass, and comprising a drive
mechanism and a mechanism housing.
[0004] It is proposed that the mechanism housing has a housing
cover that is provided to close a chamber in which the drive
mechanism is disposed and that has at least one fastening means
that, in at least one operating state, at least partially fastens
the vibration absorber device. In particular, a "hand power tool"
is to be understood to include all hand power tools considered
appropriate by persons skilled in the art, such as, in particular,
percussion drills, demolition hammers, rotary hammers, percussion
hammers, rotary percussion screwdrivers and/or, advantageously,
rotary and/or chipping hammers. A "vibration absorber device" is to
be understood to be, in particular, a device that in at least one
operating state generates, upon a hand power tool machine housing
and/or upon the mechanism housing and, in particular, upon at least
a handle of the hand power tool, a force that counteracts a
vibration, in particular of the hand power tool housing. The
vibration absorber device thereby advantageously enables the hand
power tool to be operated with little vibration. Preferably, the
vibration absorber device operates passively, i.e. without an
energy supply, apart from the vibration energy. In particular, the
term "absorber spring" is to be understood to be a spring provided
to transfer to the absorber mass, in particular directly, a force
that accelerates and/or retards the absorber mass. Advantageously,
the absorber spring is realized as a helical compression spring.
Alternatively or additionally, the absorber spring could have a
rectangular cross section perpendicularly in relation to a spring
direction, or a plurality of absorber springs could be disposed in
an interleaved manner and/or coaxially. Likewise alternatively or
additionally, the absorber spring could be realized as a different
torsion, spiral, tension and/or gas spring considered appropriate
by persons skilled in the art. An "absorber mass" is to be
understood to be, in particular, a unit provided to reduce the
vibration, in particular of the hand power tool housing, through an
inertia by means of an acceleration force and/or a retardation
force, in that, advantageously, it vibrates with an angle of phase
displacement in relation to the hand power tool housing. In
particular, a "drive mechanism" is to be understood to be a
mechanism that converts a motion of a drive motor into a work
motion, in particular a percussive motion. A "mechanism housing" is
to be understood to be, in particular, a housing in which at least
the drive mechanism is disposed in a protected manner.
Advantageously, the mechanism housing is realized so as to be at
least partially integral with the hand power tool housing.
Advantageously, the mechanism housing is provided to remove bearing
forces, at least of the drive mechanism. A "housing cover" is to be
understood to be, in particular, an element of the mechanism
housing that is realized so as to be non-destructively separable
from another element of the mechanism housing, in particular a
housing shell. Preferably, the housing cover is provided to close
an opening in the other element of the mechanism housing, in
particular an opening provided for mounting the drive mechanism.
Advantageously, the housing cover is free of bearing forces of the
drive mechanism. Particularly advantageously, the housing cover
transfers, in particular, mainly forces of the vibration absorber
device and, in particular, forces that act upon the bearing cover
from outside. "Provided" is to be understood to mean, in
particular, specially equipped and/or designed. In particular, the
term "close" is to be understood to mean that the housing cover
covers over an opening of the other element of the mechanism
housing, in particular a housing shell, when in a state of
operational readiness. The housing cover thereby protects the
chamber against soiling, i.e. it prevents dirt and, in particular,
dust from entering through the opening to the drive mechanism. A
"fastening means" is to be understood to be, in particular, a means
provided to effect upon the vibration absorber device a force that
immovably fastens at least one element of the vibration absorber
device, preferably a holding part, relative to the mounted housing
cover. Advantageously, the fastening means is realized so as to be
at least partially integral with the housing cover. The fastening
means is realized as a groove, as part of a screwed connection, as
part of a latched connection and/or as part of another connection
considered appropriate by persons skilled in the art. The design
according to the invention makes it possible to achieve, with a
simple structure, a particularly robust, compact and inexpensive
hand power tool that can be operated with particularly little
vibration. In particular, dispensing with an additional absorber
cover makes it possible to achieve a particularly light hand power
tool having an effective dissipation of heat from the drive
mechanism.
[0005] In a further design, it is proposed that the vibration
absorber device and the drive mechanism are disposed in the chamber
closed by the housing cover, i.e. the vibration absorber device is
disposed on an inner side of the housing cover. Advantageously, the
chamber is realized as a grease chamber of the hand power tool.
Since the vibration absorber device is disposed in the chamber, it
is protected, in a structurally simple and particularly
advantageous manner, against external influences such as dirt and
mechanical damage. Further, the vibration absorber device can be
lubricated, together with the drive mechanism, in a non-elaborate
manner, such that there is little wear and good utilization of
lubricant can be achieved. In addition, the vibration absorber
device is rapidly heated by the drive mechanism, for example after
a cold start, thereby further reducing wear and rendering possible
a very constant characteristic frequency of the vibration absorber
device.
[0006] Furthermore, it is proposed that the housing cover and the
vibration absorber device constitute a structural unit that can be
preassembled, such that assembly is advantageously non-elaborate.
The expression "constitute a structural unit that can be
preassembled" is to be understood to mean, in particular, that the
housing cover and the vibration absorber device can be fixedly
connected to each other in an assembly operation, in particular
before the housing cover is fastened to the mechanism housing. As a
result, the housing cover and the vibration absorber device can be
connected to form a mountable unit. Advantageously, the housing
cover and the vibration absorber device can be connected to each
other such that they can be mounted jointly. Particularly
advantageously, the housing cover and the vibration absorber device
can be connected to each other such that they can transfer the
acceleration force and/or a counter force of the acceleration
force.
[0007] Further, it is proposed that at least the absorber spring,
in at least one operating state, effects a fastening force upon the
housing cover, enabling assembly to be achieved in a particularly
non-elaborate manner. In particular, the expression "effect a
fastening force" is to be understood to mean that the absorber
spring exerts upon the housing cover a force that counteracts a
motion of at least a part of the vibration absorber device.
Advantageously, the fastening force counteracts a motion of a
holding part of the vibration absorber device. Preferably, the
fastening force prevents a motion of the holding parts.
[0008] In addition, it is proposed that the drive mechanism has a
percussion mechanism, wherein the percussion mechanism and the
vibration absorber device are at least partially disposed on at
least one same plane that is aligned perpendicularly in relation to
a spring direction, thereby making it possible to achieve a
particularly effective vibration damping and, advantageously, good
thermal coupling between the percussion mechanism and the vibration
absorber device, and an advantageous utilization of space. A
"percussion mechanism" is to be understood to be, in particular, a
device that converts a rotary motion, in particular of the drive
motor, into a linear percussive motion. Advantageously, the
percussion mechanism is realized as a hammer percussion mechanism.
Alternatively, the percussion mechanism could be realized as a
ratchet percussion mechanism or as another percussion mechanism
considered appropriate by persons skilled in the art. In
particular, the expression, "at least partially disposed on a
plane" is to be understood to mean that the plane intersects the
percussion mechanism. A "spring direction" is to be understood to
be, in particular, at least one direction in which the absorber
spring must be loaded so as to be most able to elastically store
energy. Advantageously, the absorber spring is realized so as to be
elastically deformable in a spring direction by at least 25% of a
length in a non-loaded state. Advantageously, the vibration
absorber device at least partially encloses the percussion
mechanism. This means that the vibration absorber device surrounds
at least a point of the percussion mechanism on a plane by more
than 180 degrees.
[0009] Furthermore, it is proposed that the vibration absorber
device has at least one first and one second holding part, wherein
the first holding part and the second holding part are supported
against each other through the absorber spring, such that the
structural space required is particularly small, and an
advantageously rectilinear flux of force can be achieved. A
"holding part" is to be understood to be, in particular, an element
of the vibration absorber device that, in a mounted operating
state, is connected to the housing cover so as to be immovable
relative to the housing cover. Advantageously, forces resulting
from an acceleration are transferred by the holding part from the
absorber spring to the housing cover. Preferably, the holding part
and the absorber spring are directly connected to each other. In
particular, the holding part is a component realized so as to be
separate from the mechanism housing and, preferably, from a housing
cover. Advantageously, the holding part, when in a mounted
operating state, exerts a force upon at least one element of a
drive mechanism. In particular, the expression "through the
absorber spring" is to be understood to mean that the absorber
spring, as viewed in the spring direction, completely encloses the
holding part. In this case, the holding part and the region of the
spring that encloses the holding part are at least partially
disposed on one same plane that is aligned perpendicularly in
relation to the spring direction. "Bear against each other" is to
be understood to mean, in particular, that the first and the second
holding part are connected to each other so as to be immovable
relative to each other during operation. Preferably, the second
holding part bears in an inelastic manner exclusively on the first
holding part, i.e., in particular, the second holding part is
unconnected to the transmission housing.
[0010] In an advantageous realization of the invention, it is
proposed that the vibration absorber device has at least one
holding part and has at least one spring receiver that, in at least
one operating state, exerts an acceleration force upon the absorber
mass and, in at least one operating state, supports a counter force
of the acceleration force on the holding part, making it possible
to achieve a particularly small structural space requirement and
low costs. Advantageously, the spring receiver exerts the
acceleration force at one instant and, at another instant, supports
the counter force. A "spring receiver" is to be understood to be,
in particular, an element of the vibration absorber device that is
disposed in a flux of force between the absorber spring and the
absorber mass. Advantageously, the spring receiver is connected to
the absorber mass in a mechanically fixed manner. Preferably, the
spring receiver is movable relative to the mechanism housing. In
particular, an "acceleration force" is to be understood to be a
force that accelerates and/or retards the absorber mass. A "counter
force" is to be understood to be, in particular, a force that
supports the absorber spring on one side when another side of the
absorber spring exerts the acceleration force upon the absorber
mass.
[0011] In a further design, it is proposed that the vibration
absorber device has at least one support element that, in at least
one operating state, presses the spring receiver against the
absorber spring, making it possible to achieve a particularly
non-elaborate design, as well as an advantageous spring
characteristic of the vibration absorber device and an advantageous
tolerance compensation. In particular, it is possible to dispense
with a positive, integral and/or frictional connection between the
spring receiver and the absorber mass. A "support element" is to be
understood to be, in particular, an element that, in at least one
operating state, effects upon the spring receiver a force that
counteracts a force that is effected by the absorber spring upon
the spring receiver. Advantageously, the support element is
realized as a cylindrical compression spring, as an elastomer part,
as a zigzag or disk spring, and/or as another element considered
appropriate by persons skilled in the art. Preferably, the force of
the support element upon the spring receiver, in at least one
operating state, is always significantly less, advantageously, than
a force of the absorber spring on the same spring receiver.
"Significantly less" in this context is to be understood to mean,
in particular, less than 50%, advantageously less than 25%,
particularly advantageously less than 10% of the force of the
absorber spring. Alternatively, it would also be possible to
dispense with support elements in the vibration absorber
device.
[0012] Furthermore, it is proposed that the absorber spring is
disposed entirely in an axial region of the absorber mass, thereby
making it possible to achieve an advantageously small structural
length in the spring direction. An "axial region of the absorber
mass" is to be understood to be, in particular, a region delimited
by two planes that are aligned perpendicularly in relation to the
spring direction and that intersect the absorber mass.
DRAWING
[0013] Further advantages are given by the following description of
the drawing. Four exemplary embodiments of the invention are
represented in the drawing. The drawing, the description and the
claims contain numerous features in combination. Persons skilled in
the art will, expediently, also consider the features individually
and combine them to form appropriate, further combinations.
[0014] In the drawing:
[0015] FIG. 1 shows a hand power tool according to the invention,
comprising a vibration absorber device fastened to a housing
cover,
[0016] FIG. 2 shows a section through the hand power tool from FIG.
1,
[0017] FIG. 3 shows a housing cover and the vibration absorber
device of the hand power tool from FIG. 1,
[0018] FIG. 4 shows a section (A-A) through the housing cover and
the vibration absorber device,
[0019] FIG. 5 shows a partial section of the vibration absorber
device of the hand power tool from FIG. 1, in a top view,
[0020] FIG. 6 shows a section (B-B) of the vibration absorber
device of the hand power tool from FIG. 1, in a front view,
[0021] FIG. 7 shows the vibration absorber device of the hand power
tool from FIG. 1, in a side view,
[0022] FIG. 8 shows a partial section of an alternative exemplary
embodiment of the vibration absorber device from FIG. 1, comprising
an absorber mass constructed from two mass parts,
[0023] FIG. 9 shows a section (C-C) of the vibration absorber
device from FIG. 8, in a front view,
[0024] FIG. 10 shows a partial section (D-D) of the vibration
absorber device from FIG. 8, in a side view,
[0025] FIG. 11 shows a further, alternative exemplary embodiment of
the vibration absorber device from FIG. 1, comprising two holding
parts, which are supported on each other,
[0026] FIG. 12 shows a section (E-E) of the vibration absorber
device from FIG. 11, in a front view,
[0027] FIG. 13 shows a partial section of a further, alternative
exemplary embodiment of the vibration absorber device from FIG. 1,
comprising a spring receiver that is movable relative to the
absorber mass, and
[0028] FIG. 14 shows a section (F-F) of the vibration absorber
device of FIG. 13, in a front view.
DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0029] FIG. 1 shows a hand power tool 10a according to the
invention, comprising a vibration absorber device 12a and a drive
mechanism 18a, and comprising a mechanism housing 20a that has a
metallic housing cover 22a. The hand power tool 10a is realized as
a rotary and chipping hammer. The mechanism housing 20a encloses a
chamber 24a, in which the drive mechanism 18a and the vibration
absorber device 12a are disposed. Further, the hand power tool 10a
has a main handle 44a, an insert tool fastening device 46a, a motor
housing 48a and an auxiliary handle 50a. On a side of the mechanism
housing 20a that faces away from the insert tool fastening device
46a, the main handle 44a is connected to the mechanism housing 20a
and to the motor housing 48a. On a side that faces toward the
insert tool fastening device 46a, the auxiliary handle 50a is
connected to the mechanism housing 20a.
[0030] FIG. 2 shows a section through the mechanism housing 20a,
which, besides the housing cover 22a, has a housing shell 52a. The
vibration absorber device 12a and the drive mechanism 18a are
disposed in the chamber 24a. The drive mechanism 18a has a
percussion mechanism 28a, a first and a second transmission element
54a, 56a for rotary operation, and a switchover mechanism 58a. The
percussion mechanism 28a is realized as a hammer percussion
mechanism. The first transmission element 54a is additionally
realized as an eccentric element of the percussion mechanism 28a.
Furthermore, the percussion mechanism 28a has a piston 59a, a
hammer tube 60a and, not represented in greater detail, a striker
and a ram. The second transmission element 56a drives the hammer
tube 60a in rotation. The rotary motion of the hammer tube 60a can
be switched off by the switchover mechanism 58a in a manner
considered appropriate by persons skilled in the art.
[0031] The housing cover 22a of the mechanism housing 20a is
disposed on a side of the housing shell 52a that is opposite the
motor housing 48a. It closes an assembly opening located there, and
thus closes the chamber 24a. The hand power tool 10a has a seal,
not represented in greater detail, which is disposed between the
housing cover 22a and the housing shell 52a. The vibration absorber
device 12a and the drive mechanism 18a are thereby protected
against soiling. The chamber 24a is realized as a grease chamber,
i.e. a common, permanent lubrication is provided in the chamber.
The vibration absorber device 12a and the drive mechanism 18a are
disposed in the chamber 24a closed by the housing cover 22a.
[0032] As shown by FIGS. 3 to 7, the housing cover 22a has three
fastening means 26a. The fastening means 26a are realized as
formed-on webs. The fastening means 26a have fastening surfaces 62a
aligned perpendicularly in relation to a spring direction 30a. The
fastening means 26a fasten after mounting of a structural unit,
i.e. after the vibration absorber device 12a has been inserted in
the cover, and during operation fasten the vibration absorber
device 12a in the spring direction 30a. For this purpose, during a
mounting operation the vibration absorber device 12a is compressed
in the spring direction 30a and inserted in the housing cover 22a.
As a result, through biasing in the spring direction 30a, absorber
springs 14a of the vibration absorber device 12a effect a fastening
force upon the housing cover 22a after mounting of a structural
unit and during operation. The fastening force fastens the
vibration absorber device 12a non-positively and perpendicularly in
relation to the spring direction 30a, to the housing cover 22a. The
vibration absorber device 12a and the housing cover 22a thus form a
structural unit that can be preassembled, i.e. the vibration
absorber device 12a and the housing cover 22a together, and
separately from the housing shell 52a, form a unit that is stable
per se.
[0033] After the housing cover 22a has been mounted on the housing
shell 52a, the housing shell 52a effects a fastening force upon the
vibration absorber device 12a, in a region not represented in
greater detail. The fastening force acts perpendicularly in
relation to the spring direction 30a. Alternatively or
additionally, the vibration absorber device 12a could be latched,
screwed, adhesive bonded and/or connected to the housing cover 22a
in another manner considered appropriate by persons skilled in the
art.
[0034] The percussion mechanism 28a and the vibration absorber
device 12a are disposed partially on the same planes, which are
aligned perpendicularly in relation to a spring direction 30a, i.e.
the percussion mechanism 28a and the vibration absorber device 12a
are disposed partially adjacently. A region of the vibration
absorber device 12a that faces toward the insert tool fastening
device 46a is disposed between the housing cover 22a and the
percussion mechanism 28a. This region has no functional component
apart from the vibration absorber device 12a.
[0035] The vibration absorber device 12a is realized so as to be
mirror-symmetrical when in a non-operative state. It has the four
absorber springs 14a, an absorber mass 16a, two holding parts 32a,
two spring receivers 36a, and two spring receiver fastening devices
64a. The two holding parts 32a are realized as like parts, i.e.
they have the same shape, but mirrored in relation to each other.
In addition, the holding parts 32a have a slight oversize relative
to the housing cover 22a. Outsides 66a of the holding parts 32a,
which face toward or away from the insert tool fastening device
46a, fasten the vibration absorber device 12a in the housing cover
22a. The absorber springs 14a, the absorber mass 16a, the two
spring receivers 36a and the two spring receiver fastening devices
64a are disposed between the holding parts 32a. The spring
receivers 36a and the spring receiver fastening devices 64a are
produced, at least partially, from plastic.
[0036] The holding parts 32a have guide surface 68a, which guide
the absorber mass 16a in the spring direction 30a during operation.
For this purpose, the holding parts 32a enclose the absorber mass
16a on a plane that is realized perpendicularly in relation to the
spring direction 30a. In this exemplary embodiment, the holding
parts 32a enclose the absorber mass 16a completely. Alternatively,
the holding parts 32 could enclose the absorber mass 16a by more
than 180 degrees. The holding parts 32a guide the absorber mass 16a
on surfaces disposed farthest from a center of gravity 70a of the
absorber mass 16a, enabling slight guiding forces and a slight
friction to be achieved. Alternatively or additionally, a housing
cover could also guide the absorber mass 16a and/or the absorber
spring 14a. Furthermore, the holding parts 32a each have spring
fastening devices 72a, which fasten the absorber springs 14a. For
this purpose, the absorber springs 14a are screwed onto the spring
fastening devices 72a.
[0037] The four absorber springs 14a are each mechanically
connected in a fixed manner on one side to the holding parts 32a,
and on one side to the spring receivers 36a. The spring receivers
36a, as viewed perpendicularly in relation to the spring direction
30a, have a cross-shaped cross section (FIG. 5). On a side that
faces toward the center of gravity 70a of the absorber mass 16a,
the spring receivers 36a extend into recesses 74a of the absorber
mass 16a. The spring receivers 36a in this case are supported on
the absorber mass 16a. During a mounting operation, the spring
receiver fastening devices 64a are pushed onto the absorber mass
16a and fix the spring receivers 36a, such that a positive
connection is produced between the spring receivers 36a and the
absorber mass 16a. The spring forces of the absorber springs 14a
fasten the spring receiver fastening device 64a.
[0038] In addition, the vibration absorber device 12a could have
damping elements, not represented in greater detail, which damp an
impact of the absorber mass 16a on an end stop. For example, the
damping elements could be disposed between the spring receivers 36a
and the holding parts 32a inside the absorber springs 14a, in a
guide of the holding parts 32a or on the housing cover 22a.
[0039] The absorber mass 16a has a homogeneous cross section in the
spring direction 30a. The cross section is formed by means of a bar
extrusion method. Absorber masses are cut off from a bar by a
machine and, in the same working step, are provided with recesses
for receiving spring receivers. Alternatively or additionally, an
absorber mass could have a plurality of mass parts. Advantageously,
at least one of the mass parts likewise has a homogeneous cross
section. Particularly advantageously, at least one of the mass
parts preferably has, for the most part, a standard cross section
along at least one direction.
[0040] Three further exemplary embodiments of the invention are
shown in FIGS. 8 to 14. To distinguish the exemplary embodiments,
the letter a in the references of the exemplary embodiment in FIGS.
1 to 7 is replaced by the letters b to d in the references of the
exemplary embodiments in FIGS. 8 to 14. The descriptions that
follow are limited substantially to the differences between the
exemplary embodiments and, in respect of components, features and
functions that remain the same; reference may be made to the
description of the other exemplary embodiments, in particular in
FIGS. 1 to 7.
[0041] The exemplary embodiment of FIGS. 8 to 10 relates, as
described in the exemplary embodiment of FIGS. 1 to 7, to a hand
power tool 10b according to the invention, having a vibration
absorber device 12b, represented in FIGS. 8 to 10, a drive
mechanism 18b and a mechanism housing 20b having a housing cover
22b and a housing shell 52b. The housing cover 22b, when in a state
of operational readiness, closes a chamber 24b, in which the drive
mechanism 18b is disposed. The housing cover 22b has fastening
means 26b that, in a state of operational readiness, fasten the
vibration absorber device 12b.
[0042] The vibration absorber device 12b has four absorber springs
14b, an absorber mass 16b and two holding parts 32b. The holding
parts 32b are realized as like parts. Each holding part 32b has two
spring fastening devices 72b and two guide means 76b. The guide
means 76b are realized as rods formed onto a base plate 78b of the
holding parts 32b. The guide means 76b engage in recesses 80b of
the absorber mass 16b and guide the latter in the spring direction
30b. Alternatively, guide means 76b could also extend fully through
the absorber mass 16b in the spring direction 30b.
[0043] The absorber mass 16b has a first and a second mass part
82b, 84b. The first mass part 82b, which faces toward a percussion
mechanism 28b and which is represented at the bottom in FIG. 9, is
approximately as heavy as the second mass part 84b. In general, a
heaviest mass part has a mass that, at most, is four times as great
as a lightest mass part.
[0044] A division between the two mass parts 82b, 84b runs parallel
to the spring direction 30b and substantially parallel to a main
extent of the absorber mass 16b. Alternatively, a division could
also be disposed perpendicularly in relation to a main extent of an
absorber mass or perpendicularly in relation to the spring
direction. The mass parts are screwed to each other in the center.
In addition, the mass parts 82b, 84b are clamped to each other on
outer sides 86b by latching hooks 88b. The absorber mass 16b
encloses the absorber springs 14b by more than 180 degrees, in this
example completely, on a plane aligned perpendicularly in relation
to the spring direction 30b. In the enclosed regions, the absorber
mass 16b guides the absorber springs 14b.
[0045] The exemplary embodiment of FIGS. 11 and 12 relates, as
described in the exemplary embodiments of FIGS. 1 to 7, to a hand
power tool 10c according to the invention, having a vibration
absorber device 12c, represented in FIGS. 11 and 12, a drive
mechanism 18c and a mechanism housing 20c having a housing cover
22c and a housing shell 52c. The housing cover 22c, when in a state
of operational readiness, closes a chamber 24c, in which the drive
mechanism 18c is disposed. The housing cover 22c has fastening
means 26c that, in a state of operational readiness, fasten the
vibration absorber device 12c.
[0046] The vibration absorber device 12c has a first and a second
holding part 32c, 34c. The first holding part 32c is disposed
facing toward an insert tool fastening device 46c. The second
holding part 34c is disposed facing away from the insert tool
fastening device 46c. The first holding part 32c and the second
holding part 34c are supported against each other through the
absorber springs 14c. For this purpose, the two holding parts 32c,
34c each have two rod-shaped formed-on elements 90c, 92c. The
formed-on elements 90c of the first holding part 32c extend through
two of the absorber springs 14c. In this case, the formed-on
elements 90c guide the absorber springs 14c. Ends of the formed-on
elements 90c, which face away from a base plate 78c of the first
holding part 32c, are movably mounted in a recess, or bore, of the
second holding part 34c. The formed-on elements 92c of the second
holding part 34c likewise extend through and guide two of the
absorber springs 14c. Ends of the formed-on elements 92c, which
face away from a base plate 78c of the second holding part 34c,
extend through a recess, or bore, of the first holding part 32c. On
a side of the first holding part 32c that faces away from the base
plate 78c of the second holding part 34c, the formed-on elements
92c are latched on the first holding part 32c. The vibration
absorber device 12c thus has more than two guide rods 90c, 92c that
guide the absorber mass 16c.
[0047] It can be seen from FIG. 12 that the outer absorber springs
14c are disposed somewhat deeper, i.e. closer to the drive
mechanism 18c, than the inner absorber springs 14c. In addition,
all, i.e. the four, absorber springs 14c are partially disposed on
a plane that is aligned perpendicularly in relation to the spring
direction 30c. As a result, the vibration absorber device 12c can
be integrated into the housing cover 22cin a particularly
space-saving manner. Furthermore, only one of the two holding parts
32c, 34c is mechanically connected to the mechanism housing 20c in
a fixed manner.
[0048] The exemplary embodiment of FIGS. 13 and 14 relates, as
described in the exemplary embodiments of FIGS. 1 to 7, to a hand
power tool 10d according to the invention, having a vibration
absorber device 12d, represented in FIGS. 13 and 14, a drive
mechanism 18d and a mechanism housing 20d having a housing cover
22d and a housing shell 52d. The housing cover 22d, when in a state
of operational readiness, closes a chamber 24d, in which the drive
mechanism 18d is disposed. The housing cover 22d has fastening
means 26d that, in a state of operational readiness, fasten the
vibration absorber device 12d.
[0049] The vibration absorber device 12d has two absorber springs
14d, an absorber mass 16d, a first and a second holding part 32d, a
first and a second spring receiver 36d, 38d, and four support
elements 40d, 42d. The holding parts 32d are pushed onto the
absorber mass 16d. There, the holding parts 32d are secured with
locking elements 94d. The locking elements 94d are realized as
clamping sleeves, but could also be realized as other units
considered appropriate by persons skilled in the art. The holding
parts 32d are mounted on the absorber mass 16d so as to be movable
in the spring direction 30d, this being between two locking
elements 94d and a middle offset 96d in each case. The middle
offset 96d extends perpendicularly in relation to the spring
direction 30d.
[0050] The first holding part 32d and the first spring receiver 36d
are disposed facing toward the insert tool fastening device 46d.
The absorber mass 16d, when in an operating state, moves the second
spring receiver 38d in the direction of the insert tool fastening
device 46d. In this case, the second spring receiver 38d exerts an
acceleration force upon the absorber mass 16d. The acceleration
force brakes the absorber mass 16d. The second spring receiver 38d
in this case transfers a motional energy of the absorber mass 16d
to the absorber springs 14d, via the locking elements 94d. The
absorber springs 14d buffer this energy. After the absorber springs
14d have arrested the absorber mass 16d relative to the holding
parts 32d, the absorber springs 14d deliver the energy back to the
absorber mass 16d and, in so doing, accelerate the absorber mass
16d. In this movement of the absorber mass 16d from a central
position in the direction of the insert tool fastening device 46d,
the first spring receiver 36d supports a counter force of the
acceleration force at the first holding part 32d. After the
absorber mass 16d has crossed over a central position, the same
operation is effected, in a mirror inverted manner, in the opposite
direction.
[0051] The support elements 40d, 42d in two differing operating
states press the spring receivers 36d, 38d against the absorber
springs 14d. The support elements 40d, 42d are realized as support
springs. A force of the support elements 40d, 42d in this case is
significantly less than the acceleration force of the absorber
springs 14d. The support elements 40d, 42d in this case are aligned
coaxially in relation to the absorber springs 14d. The absorber
springs 14d are disposed entirely in an axial region, i.e.
laterally next to the absorber mass 16d.
* * * * *